A graphical display system for animating mapped cardiac potentials is described. The system displays recorded voltages from 121 epicardial electrodes simultaneously on a computer monitor using color to indicate the magnitude of the voltage. Numerous options accessible through the mouse-driven user interface provide the user with a high degree of interaction with the data. The user can observe the changes in the recorded voltages over time by defining a portion of the data over which to animate the voltages. Animation speeds of up to 2 1/4 frames per second can be achieved, depending on the workstation used. Use of the graphical display system provides a new tool for studying the electrical conduction properties of the heart. Through its use, a more complete understanding (and potentially a more effective treatment) of arrhythmias might be achieved.>

The authors note that knowledge of the extracellular potential gradient field of the defibrillation shock and the cardiac-tissue response to the shock should lead to better understanding of the mechanism of defibrillation and stimulate improvement of defibrillation techniques. By measuring the potential distribution of the defibrillation shock throughout the heart and the location of the recording electrodes, the potential gradient field may be calculated. By recording local electrograms throughout the heart immediately before and after the shock, the tissue response to the shock can be evaluated.>